Lesson 1 Flashcards
Approximately how many stars are there in the Milky Way galaxy?
More than 100,000,000,000 (100 billion)
How big is the Milky Way in comparison to the other nearby galaxies?
It is the second largest in the local group of about 40 galaxies
What is the name of the Milky Way’s local group?
Laniakea
What is the unit of measurement used inside the solar system?
Astronomical units (AU) 1 AU = 150 million km
What is the unit of measurement used outside of the solar system?
Light years (ly) 1 ly = 9.46 trillion km
What is 1 light second equivalent to?
300,000 km/second
- 300,000km/s x 60 seconds x 60 minutes x 24 hours x 365 days = 1 light year
How is observing the light from stars like looking into the past?
When we say that a star is 2,000 light years away (distance) we mean that the star’s light has taken 2,000 years to reach us, and thus it is like looking 2,000 years into the past
How old is the Universe?
Approximately 13.7 billion years old
- this is based on how long it has taken us to see the light from the farthest point in the observable universe (the horizon of the universe)
What is a galaxy?
Many stars and planets that orbit a common centre
What is a galaxy cluster?
When there are approximately a dozen galaxies in close proximity to one another
What is a supercluster?
What is a supercluster?
What is the definition of the Universe?
The sum total of all matter and energy
Describe what the Voyage scale model does?
It shrinks the universe to 1:10,000,000,000 its size
What is the formula for distance?
D= speed x time
What is nuclear fusion?
The process in which light atomic nuclei fuse to make heavier ones
